Indoor position systems (IPSs) comprise a network of devices used to wirelessly locate objects or people inside a building. Instead of using satellites, an IPS relies on nearby anchors (e.g., nodes with a known position), which either actively locate tags or provide ambient location or environmental context for devices to get sensed. These anchors can use different ways to determine positions of objects or people including: choke point concepts, grid concepts, long-range sensor concepts, angle of arrival, time of arrival, signal strength indication, or inertial measurements, or combinations thereof. The localized nature of an IPS has resulted in systems making use of various optical, radio, or even acoustic technologies.
Most applications currently rely on global positioning system (GPS), and function poorly indoors as a result. Due to signal attenuation caused by construction materials, satellite based GPS signals lose significant power indoors decreasing coverage for receivers. In addition, multiple reflections at surfaces cause multi-path propagation, which can cause uncontrollable error. Indoor positioning is, however, a vehicle for the expansion of location-aware mobile computing indoors.
Other IPS platforms can be integrated into the infrastructure of buildings, but this type of service is costly and labor intensive because it involves custom engineering at each location by assimilating and analyzing radio frequency (RF) measurement data, identifying and mapping radiation sources, and studying building area floor plans and obstructions.
The above-described background relating to IPS systems is merely intended to provide a contextual overview, and is not intended to be exhaustive. Other contextual information may become further apparent upon review of the following detailed description.